Change mojo enums to be scoped enums in the generated C++ bindings.

components/mus/ws/window_tree_host_connection.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/mus/ws/window_tree_host_connection.h"
 
 #include "components/mus/ws/connection_manager.h"
 #include "components/mus/ws/window_tree_host_impl.h"
 
 namespace mus {
@@ skipping 45 matching lines @@
     : WindowTreeHostConnection(std::move(host_impl), manager),
       binding_(window_tree_host(), std::move(request)),
       client_(std::move(client)) {}
 
 WindowTreeHostConnectionImpl::~WindowTreeHostConnectionImpl() {}
 
 void WindowTreeHostConnectionImpl::OnDisplayInitialized() {
   connection_manager()->AddHost(this);
   set_window_tree(connection_manager()->EmbedAtWindow(
       window_tree_host()->root_window(),
-      mojom::WindowTree::ACCESS_POLICY_EMBED_ROOT, std::move(client_)));
+      mojom::WindowTree::kAccessPolicyEmbedRoot, std::move(client_)));
 }
 
 }  // namespace ws
 
 }  // namespace mus